This invention pertains to water purification and, more particularly, to a frame for efficiently and properly aligning a stack of water treatment membrane cells.
Untreated water from rivers, lakes, underground aquifers, and from other natural sources, as well as waste water discharged from refineries and industrial plants often contain contaminants, such as iron oxides, phenols, sulfides, oil, grease, ammonia, and particulates. If sufficient quantities of these contaminants are present, the water may not be safe to swim or drink. Furthermore, such water may corrode pipes, boilers, valves, and other equipment in oil refineries, petrochemical plants, power stations, and other industrial sites.
One way to treat water is by electrodialysis. In electrodialysis, water to be treated is fed through hundreds of electrodialysis membrane cells where it is subjected to a high voltage and sufficient current to remove substantial amounts of contaminants. If the cells are not in proper alignment, the efficiency and effectiveness of the electrodialysis cells can be seriously impaired so that sufficient levels of contaminants will not be adequately removed from the water. Improper cell alignment can also cause hot spots and damage to the cells. Misalignment of the cells can further cause water leakage which can be hazardous to operating personnel as well as unsightly and messy.
In the past, electrodialysis cells have been stacked with wooden pegs (stakes), flexible poles, steel dowel rods, wooden logs, and/or boards, such as 2 by 4 wooden boards (planks). None of these stacking aids work too well or are reliable. Such stacking aids often do not provide for proper alignment of the cells. Moreover, use of such prior art stacking aids are usually time-consuming and laborious. Wooden pegs are tedious, cumbersome, and often get stuck in the holes of the cells. Flexible poles and steel dowel rods allow undesirable curvature or stepwise stacking of the cells. Wooden logs and boards are primitive, awkward, difficult to use, and often ineffective.
Over the years various electrodialysis apparatuses, filter chambers, and other equipment have been suggested for use in cleaning water or other fluids or for other purposes. Typifying, some of these electrodialysis apparatuses, filter chambers, and other prior art equipment are those shown in U.S. Pat. Nos. 788,436; 1,529,867; 2,417,958; 3,219,573; and 3,276,190. These electrodialysis apparatuses, filter chambers, and other prior art equipment have met with varying degrees of success.
It is, therefore, desirable to provide improved equipment for stacking and aligning electrodialysis membrane cells, which overcome most, if not all, of the preceding problems.